The world is getting very much more competitive.

Size will hurt returns. Look at Berkshire Hathaway - the last five things Warren has done have generated returns that are splendid by historical standards, but now give him $100 billion in assets and measure outcomes across all of it, it doesn't look so good. We can only buy big positions, and the only time we can get big positions is during a horrible period of decline or stasis. That really doesn't happen very often.

We have a higher percentage of the intelligentsia engaged in buying and selling pieces of paper and promoting trading activity than in any past era. A lot of what I see now reminds me of Sodomand Gomorrah. You get activity feeding on itself, envy and imitation. It has happened in the past that there came bad consequences.

Just as a man working with his tools should know its limitations, a man working with his cognitive apparatus must know its limitations.

Being rational is a moral Imperative. You should never be stupider than you need to be.

People like the robber barons assumed that the doctrine of the survival of the fittest authenticated them as deserving power. You know, "I'm the richest. Therefore, I'm the best. God's in his heaven, etc." And that reaction of the robber barons was so irritating to people that it made it unfashionable to think of an economy as an ecosystem. But the truth is that it is a lot like an ecosystem. And you get many of the same results.

If you skillfully follow the multidisciplinary path, you will never wish to come back. It would be like cutting off your hands.